The 20-year-old has agreed a five-and-a-half year contract with the Premier League giants and his registration will be transferred in the coming days, even though he will be loaned back to the Championship club for the rest of the season.

Zaha is also due to undertake a medical in the next 48 hours as United wrap up the deal.

Sources have told Goal.com that Palace chairman Steve Parish, who is believed to be in Australia, had hoped to hang on to Zaha’s registration until the summer, with the two clubs agreeing a ‘guaranteed date of purchase’.

WILF MOVE GREAT FOR PALACE

Zaha going to Manchester United in the January window for £15m up front, £2m in add-ons, and a loan-back until then summer, is a great bit of business for Palace.

We have been stung too many times in the past by bigger clubs and seen talented youngsters that we've developed, leave for pittance. The likes of Wayne Routledge, Victor Moses and John Bostock all left for way less than they should have thanks to greedy agents and measly top flight clubs.

But this deal for Zaha signifies that putting time in to a youngster should be rewarded. Especially after the new Elite Player Performance Plan that has been implemented allowing Premier League teams to pick and choose the country's best kids for next to nothing, I hope this deal is a benchmark for future transfers, and that lower league teams get what they deserve.

Palace co-chairman Steve Parish has long insisted he would only go if the deal was right for the club, and he's been true to his word.

If we get Zaha back until the end of the season, then you may well see Palace in the Premier League next season, and even though we'd love to have Wilf playing for us in the top flight, you'll get nothing but love and adulation for him from the away end at Old Trafford next campaign.

- James Daly

However, Football League rules forbid such an agreement and United have been keen to complete the deal this week.

Parish had overseen the negotiations with the two clubs and was aware that Zaha met United manager Sir Alex Ferguson for talks in London on Sunday.

The Championship club used Arsenal’s interest to drive the price way beyond the £10m mark and the final fee is far beyond what the Gunners paid to beat United to the signings of Alex Oxlade-Chamberlain in 2011 and Theo Walcott in 2006.

The title challengers had initially been undecided about the framework of the deal amid concerns that the 20-year-old would be a ‘marked man’ if he remained in the Championship until the end of the season.

But United will sign Zaha this month, loan him back to Palace until the end of the season and integrate him into the Old Trafford set-up in the summer.

Speaking last Wednesday, chief executive David Gill said that United would be willing to let the newly-capped England international re-join the promotion chasers on loan.

“He is one of the players we are looking at,” said Gill. “Even if we did something with Wilfried, that would be for the summer.”

Goal.com revealed on Monday of last week that Arsenal had re-entered the race for the 20-year-old and were locked in a 50-50 battle for his signature with United ahead of both clubs holding advanced talks with Palace co-chairman Steve Parish last week.

Parish and Palace manager Ian Holloway have both consistently said that Zaha would remain a Selhurst Park employee until the end of the season, which could lead to some questions being asked by supporters of the Championship club's hierarchy.

However, although his registration will be transferred to United, he will be available to spearhead Palace’s promotion challenge.

The attacker, who can play anywhere across the front three, has been a driving force in Palace’s surge to fourth in the Championship, scoring five goals in 27 league appearances this season. He made his England debut as a substitute in the 4-2 November friendly defeat to Sweden.